diff --git a/cura/BuildVolume.py b/cura/BuildVolume.py
index b029665abd..10ae8bb87a 100755
--- a/cura/BuildVolume.py
+++ b/cura/BuildVolume.py
@@ -528,7 +528,7 @@ class BuildVolume(SceneNode):
     def _onStackChanged(self):
         if self._global_container_stack:
             self._global_container_stack.propertyChanged.disconnect(self._onSettingPropertyChanged)
-            extruders = ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId())
+            extruders = ExtruderManager.getInstance().getActiveExtruderStacks()
             for extruder in extruders:
                 extruder.propertyChanged.disconnect(self._onSettingPropertyChanged)
 
@@ -536,7 +536,7 @@ class BuildVolume(SceneNode):
 
         if self._global_container_stack:
             self._global_container_stack.propertyChanged.connect(self._onSettingPropertyChanged)
-            extruders = ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId())
+            extruders = ExtruderManager.getInstance().getActiveExtruderStacks()
             for extruder in extruders:
                 extruder.propertyChanged.connect(self._onSettingPropertyChanged)
 
diff --git a/cura/CuraApplication.py b/cura/CuraApplication.py
index dbc675a279..7e5e98adef 100755
--- a/cura/CuraApplication.py
+++ b/cura/CuraApplication.py
@@ -429,6 +429,7 @@ class CuraApplication(QtApplication):
             # Readers & Writers:
             "GCodeWriter",
             "STLReader",
+            "3MFWriter",
 
             # Tools:
             "CameraTool",
diff --git a/cura/Scene/ConvexHullDecorator.py b/cura/Scene/ConvexHullDecorator.py
index 367144abfc..ea54d64642 100644
--- a/cura/Scene/ConvexHullDecorator.py
+++ b/cura/Scene/ConvexHullDecorator.py
@@ -304,7 +304,7 @@ class ConvexHullDecorator(SceneNodeDecorator):
         if self._global_stack:
             self._global_stack.propertyChanged.disconnect(self._onSettingValueChanged)
             self._global_stack.containersChanged.disconnect(self._onChanged)
-            extruders = ExtruderManager.getInstance().getMachineExtruders(self._global_stack.getId())
+            extruders = ExtruderManager.getInstance().getActiveExtruderStacks()
             for extruder in extruders:
                 extruder.propertyChanged.disconnect(self._onSettingValueChanged)
 
@@ -314,7 +314,7 @@ class ConvexHullDecorator(SceneNodeDecorator):
             self._global_stack.propertyChanged.connect(self._onSettingValueChanged)
             self._global_stack.containersChanged.connect(self._onChanged)
 
-            extruders = ExtruderManager.getInstance().getMachineExtruders(self._global_stack.getId())
+            extruders = ExtruderManager.getInstance().getActiveExtruderStacks()
             for extruder in extruders:
                 extruder.propertyChanged.connect(self._onSettingValueChanged)
 
diff --git a/cura/Settings/ExtruderManager.py b/cura/Settings/ExtruderManager.py
index e046082b5f..1003ab5c86 100755
--- a/cura/Settings/ExtruderManager.py
+++ b/cura/Settings/ExtruderManager.py
@@ -4,7 +4,7 @@
 from PyQt5.QtCore import pyqtSignal, pyqtProperty, QObject, QVariant  # For communicating data and events to Qt.
 from UM.FlameProfiler import pyqtSlot
 
-import cura.CuraApplication #To get the global container stack to find the current machine.
+import cura.CuraApplication # To get the global container stack to find the current machine.
 from UM.Logger import Logger
 from UM.Scene.Iterator.DepthFirstIterator import DepthFirstIterator
 from UM.Scene.SceneNode import SceneNode
@@ -12,15 +12,15 @@ from UM.Scene.Selection import Selection
 from UM.Scene.Iterator.BreadthFirstIterator import BreadthFirstIterator
 from UM.Settings.ContainerRegistry import ContainerRegistry  # Finding containers by ID.
 from UM.Settings.SettingFunction import SettingFunction
-from UM.Settings.SettingInstance import SettingInstance
 from UM.Settings.ContainerStack import ContainerStack
 from UM.Settings.PropertyEvaluationContext import PropertyEvaluationContext
 
-from typing import Optional, List, TYPE_CHECKING, Union, Dict
+from typing import Optional, TYPE_CHECKING, Dict, List, Any
 
 if TYPE_CHECKING:
     from cura.Settings.ExtruderStack import ExtruderStack
     from cura.Settings.GlobalStack import GlobalStack
+    from UM.Scene.SceneNode import SceneNode
 
 
 ##  Manages all existing extruder stacks.
@@ -38,9 +38,10 @@ class ExtruderManager(QObject):
 
         self._application = cura.CuraApplication.CuraApplication.getInstance()
 
-        self._extruder_trains = {}  # Per machine, a dictionary of extruder container stack IDs. Only for separately defined extruders.
+        # Per machine, a dictionary of extruder container stack IDs. Only for separately defined extruders.
+        self._extruder_trains = {}  # type: Dict[str, Dict[str, ExtruderStack]]
         self._active_extruder_index = -1  # Indicates the index of the active extruder stack. -1 means no active extruder stack
-        self._selected_object_extruders = []
+        self._selected_object_extruders = []  # type: List[ExtruderStack]
         self._addCurrentMachineExtruders()
 
         Selection.selectionChanged.connect(self.resetSelectedObjectExtruders)
@@ -68,7 +69,7 @@ class ExtruderManager(QObject):
 
     ##  Return extruder count according to extruder trains.
     @pyqtProperty(int, notify = extrudersChanged)
-    def extruderCount(self):
+    def extruderCount(self) -> int:
         if not self._application.getGlobalContainerStack():
             return 0  # No active machine, so no extruders.
         try:
@@ -83,24 +84,10 @@ class ExtruderManager(QObject):
 
         global_container_stack = self._application.getGlobalContainerStack()
         if global_container_stack:
-            global_stack_id = global_container_stack.getId()
-
-            if global_stack_id in self._extruder_trains:
-                for position in self._extruder_trains[global_stack_id]:
-                    extruder_stack_ids[position] = self._extruder_trains[global_stack_id][position].getId()
+            extruder_stack_ids = {position: extruder.id for position, extruder in global_container_stack.extruders.items()}
 
         return extruder_stack_ids
 
-    @pyqtSlot(str, result = str)
-    def getQualityChangesIdByExtruderStackId(self, extruder_stack_id: str) -> str:
-        global_container_stack = self._application.getGlobalContainerStack()
-        if global_container_stack is not None:
-            for position in self._extruder_trains[global_container_stack.getId()]:
-                extruder = self._extruder_trains[global_container_stack.getId()][position]
-                if extruder.getId() == extruder_stack_id:
-                    return extruder.qualityChanges.getId()
-        return ""
-
     ##  Changes the active extruder by index.
     #
     #   \param index The index of the new active extruder.
@@ -117,9 +104,9 @@ class ExtruderManager(QObject):
     #
     #   \param index The index of the extruder whose name to get.
     @pyqtSlot(int, result = str)
-    def getExtruderName(self, index):
+    def getExtruderName(self, index: int) -> str:
         try:
-            return list(self.getActiveExtruderStacks())[index].getName()
+            return self.getActiveExtruderStacks()[index].getName()
         except IndexError:
             return ""
 
@@ -133,7 +120,7 @@ class ExtruderManager(QObject):
             object_extruders = set()
 
             # First, build a list of the actual selected objects (including children of groups, excluding group nodes)
-            selected_nodes = []
+            selected_nodes = []  # type: List["SceneNode"]
             for node in Selection.getAllSelectedObjects():
                 if node.callDecoration("isGroup"):
                     for grouped_node in BreadthFirstIterator(node): #type: ignore #Ignore type error because iter() should get called automatically by Python syntax.
@@ -145,14 +132,13 @@ class ExtruderManager(QObject):
                     selected_nodes.append(node)
 
             # Then, figure out which nodes are used by those selected nodes.
-            global_stack = self._application.getGlobalContainerStack()
-            current_extruder_trains = self._extruder_trains.get(global_stack.getId())
+            current_extruder_trains = self.getActiveExtruderStacks()
             for node in selected_nodes:
                 extruder = node.callDecoration("getActiveExtruder")
                 if extruder:
                     object_extruders.add(extruder)
                 elif current_extruder_trains:
-                    object_extruders.add(current_extruder_trains["0"].getId())
+                    object_extruders.add(current_extruder_trains[0].getId())
 
             self._selected_object_extruders = list(object_extruders)
 
@@ -168,14 +154,7 @@ class ExtruderManager(QObject):
 
     @pyqtSlot(result = QObject)
     def getActiveExtruderStack(self) -> Optional["ExtruderStack"]:
-        global_container_stack = self._application.getGlobalContainerStack()
-
-        if global_container_stack:
-            if global_container_stack.getId() in self._extruder_trains:
-                if str(self._active_extruder_index) in self._extruder_trains[global_container_stack.getId()]:
-                    return self._extruder_trains[global_container_stack.getId()][str(self._active_extruder_index)]
-
-        return None
+        return self.getExtruderStack(self._active_extruder_index)
 
     ##  Get an extruder stack by index
     def getExtruderStack(self, index) -> Optional["ExtruderStack"]:
@@ -186,16 +165,7 @@ class ExtruderManager(QObject):
                     return self._extruder_trains[global_container_stack.getId()][str(index)]
         return None
 
-    ##  Get all extruder stacks
-    def getExtruderStacks(self) -> List["ExtruderStack"]:
-        result = []
-        for i in range(self.extruderCount):
-            stack = self.getExtruderStack(i)
-            if stack:
-                result.append(stack)
-        return result
-
-    def registerExtruder(self, extruder_train, machine_id):
+    def registerExtruder(self, extruder_train: "ExtruderStack", machine_id: str) -> None:
         changed = False
 
         if machine_id not in self._extruder_trains:
@@ -214,23 +184,20 @@ class ExtruderManager(QObject):
         if changed:
             self.extrudersChanged.emit(machine_id)
 
-    def getAllExtruderValues(self, setting_key):
-        return self.getAllExtruderSettings(setting_key, "value")
-
     ##  Gets a property of a setting for all extruders.
     #
     #   \param setting_key  \type{str} The setting to get the property of.
     #   \param property  \type{str} The property to get.
     #   \return \type{List} the list of results
-    def getAllExtruderSettings(self, setting_key: str, prop: str):
+    def getAllExtruderSettings(self, setting_key: str, prop: str) -> List:
         result = []
-        for index in self.extruderIds:
-            extruder_stack_id = self.extruderIds[str(index)]
-            extruder_stack = ContainerRegistry.getInstance().findContainerStacks(id = extruder_stack_id)[0]
+
+        for extruder_stack in self.getActiveExtruderStacks():
             result.append(extruder_stack.getProperty(setting_key, prop))
+
         return result
 
-    def extruderValueWithDefault(self, value):
+    def extruderValueWithDefault(self, value: str) -> str:
         machine_manager = self._application.getMachineManager()
         if value == "-1":
             return machine_manager.defaultExtruderPosition
@@ -321,7 +288,7 @@ class ExtruderManager(QObject):
     ##  Removes the container stack and user profile for the extruders for a specific machine.
     #
     #   \param machine_id The machine to remove the extruders for.
-    def removeMachineExtruders(self, machine_id: str):
+    def removeMachineExtruders(self, machine_id: str) -> None:
         for extruder in self.getMachineExtruders(machine_id):
             ContainerRegistry.getInstance().removeContainer(extruder.userChanges.getId())
             ContainerRegistry.getInstance().removeContainer(extruder.getId())
@@ -331,24 +298,11 @@ class ExtruderManager(QObject):
     ##  Returns extruders for a specific machine.
     #
     #   \param machine_id The machine to get the extruders of.
-    def getMachineExtruders(self, machine_id: str):
+    def getMachineExtruders(self, machine_id: str) -> List["ExtruderStack"]:
         if machine_id not in self._extruder_trains:
             return []
         return [self._extruder_trains[machine_id][name] for name in self._extruder_trains[machine_id]]
 
-    ##  Returns a list containing the global stack and active extruder stacks.
-    #
-    #   The first element is the global container stack, followed by any extruder stacks.
-    #   \return \type{List[ContainerStack]}
-    def getActiveGlobalAndExtruderStacks(self) -> Optional[List[Union["ExtruderStack", "GlobalStack"]]]:
-        global_stack = self._application.getGlobalContainerStack()
-        if not global_stack:
-            return None
-
-        result = [global_stack]
-        result.extend(self.getActiveExtruderStacks())
-        return result
-
     ##  Returns the list of active extruder stacks, taking into account the machine extruder count.
     #
     #   \return \type{List[ContainerStack]} a list of
@@ -357,10 +311,7 @@ class ExtruderManager(QObject):
         if not global_stack:
             return []
 
-        result = []
-        if global_stack.getId() in self._extruder_trains:
-            for extruder in sorted(self._extruder_trains[global_stack.getId()]):
-                result.append(self._extruder_trains[global_stack.getId()][extruder])
+        result = list(global_stack.extruders.values())
 
         machine_extruder_count = global_stack.getProperty("machine_extruder_count", "value")
 
@@ -406,7 +357,7 @@ class ExtruderManager(QObject):
 
     # After 3.4, all single-extrusion machines have their own extruder definition files instead of reusing
     # "fdmextruder". We need to check a machine here so its extruder definition is correct according to this.
-    def _fixSingleExtrusionMachineExtruderDefinition(self, global_stack):
+    def _fixSingleExtrusionMachineExtruderDefinition(self, global_stack: "GlobalStack") -> None:
         expected_extruder_definition_0_id = global_stack.getMetaDataEntry("machine_extruder_trains")["0"]
         extruder_stack_0 = global_stack.extruders["0"]
         if extruder_stack_0.definition.getId() != expected_extruder_definition_0_id:
@@ -425,11 +376,11 @@ class ExtruderManager(QObject):
     #   \return A list of values for all extruders. If an extruder does not have a value, it will not be in the list.
     #           If no extruder has the value, the list will contain the global value.
     @staticmethod
-    def getExtruderValues(key):
+    def getExtruderValues(key: str) -> List[Any]:
         global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
 
         result = []
-        for extruder in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+        for extruder in ExtruderManager.getInstance().getActiveExtruderStacks():
             if not extruder.isEnabled:
                 continue
             # only include values from extruders that are "active" for the current machine instance
@@ -460,7 +411,7 @@ class ExtruderManager(QObject):
     #   \return A list of values for all extruders. If an extruder does not have a value, it will not be in the list.
     #           If no extruder has the value, the list will contain the global value.
     @staticmethod
-    def getDefaultExtruderValues(key):
+    def getDefaultExtruderValues(key: str) -> List[Any]:
         global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
         context = PropertyEvaluationContext(global_stack)
         context.context["evaluate_from_container_index"] = 1  # skip the user settings container
@@ -471,7 +422,7 @@ class ExtruderManager(QObject):
         }
 
         result = []
-        for extruder in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+        for extruder in ExtruderManager.getInstance().getActiveExtruderStacks():
             # only include values from extruders that are "active" for the current machine instance
             if int(extruder.getMetaDataEntry("position")) >= global_stack.getProperty("machine_extruder_count", "value", context = context):
                 continue
@@ -504,7 +455,7 @@ class ExtruderManager(QObject):
     #
     #   \return String representing the extruder values
     @pyqtSlot(str, result="QVariant")
-    def getInstanceExtruderValues(self, key):
+    def getInstanceExtruderValues(self, key) -> List:
         return ExtruderManager.getExtruderValues(key)
 
     ##  Get the value for a setting from a specific extruder.
@@ -517,7 +468,7 @@ class ExtruderManager(QObject):
     #   \return The value of the setting for the specified extruder or for the
     #   global stack if not found.
     @staticmethod
-    def getExtruderValue(extruder_index, key):
+    def getExtruderValue(extruder_index: int, key: str) -> Any:
         if extruder_index == -1:
             extruder_index = int(cura.CuraApplication.CuraApplication.getInstance().getMachineManager().defaultExtruderPosition)
         extruder = ExtruderManager.getInstance().getExtruderStack(extruder_index)
@@ -542,7 +493,7 @@ class ExtruderManager(QObject):
     #   \return The value of the setting for the specified extruder or for the
     #   global stack if not found.
     @staticmethod
-    def getDefaultExtruderValue(extruder_index, key):
+    def getDefaultExtruderValue(extruder_index: int, key: str) -> Any:
         extruder = ExtruderManager.getInstance().getExtruderStack(extruder_index)
         context = PropertyEvaluationContext(extruder)
         context.context["evaluate_from_container_index"] = 1  # skip the user settings container
@@ -569,7 +520,7 @@ class ExtruderManager(QObject):
     #
     #   \return The effective value
     @staticmethod
-    def getResolveOrValue(key):
+    def getResolveOrValue(key: str) -> Any:
         global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
         resolved_value = global_stack.getProperty(key, "value")
 
@@ -583,7 +534,7 @@ class ExtruderManager(QObject):
     #
     #   \return The effective value
     @staticmethod
-    def getDefaultResolveOrValue(key):
+    def getDefaultResolveOrValue(key: str) -> Any:
         global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
         context = PropertyEvaluationContext(global_stack)
         context.context["evaluate_from_container_index"] = 1  # skip the user settings container
diff --git a/cura/Settings/ExtrudersModel.py b/cura/Settings/ExtrudersModel.py
index f179dabd5a..52fc502bfc 100644
--- a/cura/Settings/ExtrudersModel.py
+++ b/cura/Settings/ExtrudersModel.py
@@ -134,7 +134,7 @@ class ExtrudersModel(UM.Qt.ListModel.ListModel):
         # Link to new extruders
         self._active_machine_extruders = []
         extruder_manager = Application.getInstance().getExtruderManager()
-        for extruder in extruder_manager.getExtruderStacks():
+        for extruder in extruder_manager.getActiveExtruderStacks():
             if extruder is None: #This extruder wasn't loaded yet. This happens asynchronously while this model is constructed from QML.
                 continue
             extruder.containersChanged.connect(self._onExtruderStackContainersChanged)
@@ -171,7 +171,7 @@ class ExtrudersModel(UM.Qt.ListModel.ListModel):
             # get machine extruder count for verification
             machine_extruder_count = global_container_stack.getProperty("machine_extruder_count", "value")
 
-            for extruder in Application.getInstance().getExtruderManager().getMachineExtruders(global_container_stack.getId()):
+            for extruder in Application.getInstance().getExtruderManager().getActiveExtruderStacks():
                 position = extruder.getMetaDataEntry("position", default = "0")  # Get the position
                 try:
                     position = int(position)
diff --git a/cura/Settings/MachineManager.py b/cura/Settings/MachineManager.py
index d65bbfddd9..ed543fcee1 100755
--- a/cura/Settings/MachineManager.py
+++ b/cura/Settings/MachineManager.py
@@ -385,7 +385,9 @@ class MachineManager(QObject):
     #   \param definition_id \type{str} definition id that needs to look for
     #   \param metadata_filter \type{dict} list of metadata keys and values used for filtering
     @staticmethod
-    def getMachine(definition_id: str, metadata_filter: Dict[str, str] = None) -> Optional["GlobalStack"]:
+    def getMachine(definition_id: str, metadata_filter: Optional[Dict[str, str]] = None) -> Optional["GlobalStack"]:
+        if metadata_filter is None:
+            metadata_filter = {}
         machines = CuraContainerRegistry.getInstance().findContainerStacks(type = "machine", **metadata_filter)
         for machine in machines:
             if machine.definition.getId() == definition_id:
@@ -412,7 +414,7 @@ class MachineManager(QObject):
 
         # Not a very pretty solution, but the extruder manager doesn't really know how many extruders there are
         machine_extruder_count = self._global_container_stack.getProperty("machine_extruder_count", "value")
-        extruder_stacks = ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId())
+        extruder_stacks = ExtruderManager.getInstance().getActiveExtruderStacks()
         count = 1  # we start with the global stack
         for stack in extruder_stacks:
             md = stack.getMetaData()
@@ -435,7 +437,7 @@ class MachineManager(QObject):
         if self._global_container_stack.getTop().findInstances():
             return True
 
-        stacks = list(ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId()))
+        stacks = ExtruderManager.getInstance().getActiveExtruderStacks()
         for stack in stacks:
             if stack.getTop().findInstances():
                 return True
@@ -448,7 +450,7 @@ class MachineManager(QObject):
             return 0
         num_user_settings = 0
         num_user_settings += len(self._global_container_stack.getTop().findInstances())
-        stacks = list(ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId()))
+        stacks = ExtruderManager.getInstance().getActiveExtruderStacks()
         for stack in stacks:
             num_user_settings += len(stack.getTop().findInstances())
         return num_user_settings
@@ -473,7 +475,7 @@ class MachineManager(QObject):
             stack = ExtruderManager.getInstance().getActiveExtruderStack()
             stacks = [stack]
         else:
-            stacks = ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId())
+            stacks = ExtruderManager.getInstance().getActiveExtruderStacks()
 
         for stack in stacks:
             if stack is not None:
@@ -638,7 +640,7 @@ class MachineManager(QObject):
         if self._active_container_stack is None or self._global_container_stack is None:
             return
         new_value = self._active_container_stack.getProperty(key, "value")
-        extruder_stacks = [stack for stack in ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId())]
+        extruder_stacks = [stack for stack in ExtruderManager.getInstance().getActiveExtruderStacks()]
 
         # check in which stack the value has to be replaced
         for extruder_stack in extruder_stacks:
diff --git a/cura/Settings/UserChangesModel.py b/cura/Settings/UserChangesModel.py
index 93274d61c9..95674e5ecd 100644
--- a/cura/Settings/UserChangesModel.py
+++ b/cura/Settings/UserChangesModel.py
@@ -43,7 +43,9 @@ class UserChangesModel(ListModel):
         global_stack = Application.getInstance().getGlobalContainerStack()
         if not global_stack:
             return
-        stacks = ExtruderManager.getInstance().getActiveGlobalAndExtruderStacks()
+
+        stacks = [global_stack]
+        stacks.extend(global_stack.extruders.values())
 
         # Check if the definition container has a translation file and ensure it's loaded.
         definition = global_stack.getBottom()
diff --git a/plugins/CuraEngineBackend/CuraEngineBackend.py b/plugins/CuraEngineBackend/CuraEngineBackend.py
index 9a5c95b04d..91a9ee0e7b 100755
--- a/plugins/CuraEngineBackend/CuraEngineBackend.py
+++ b/plugins/CuraEngineBackend/CuraEngineBackend.py
@@ -343,7 +343,7 @@ class CuraEngineBackend(QObject, Backend):
                 if not self._global_container_stack:
                     Logger.log("w", "Global container stack not assigned to CuraEngineBackend!")
                     return
-                extruders = list(ExtruderManager.getInstance().getMachineExtruders(self._global_container_stack.getId()))
+                extruders = ExtruderManager.getInstance().getActiveExtruderStacks()
                 error_keys = [] #type: List[str]
                 for extruder in extruders:
                     error_keys.extend(extruder.getErrorKeys())
diff --git a/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py b/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py
index 3bd6d79198..3953625c7e 100644
--- a/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py
+++ b/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py
@@ -178,7 +178,7 @@ class ProcessSlicedLayersJob(Job):
         # Find out colors per extruder
         global_container_stack = Application.getInstance().getGlobalContainerStack()
         manager = ExtruderManager.getInstance()
-        extruders = list(manager.getMachineExtruders(global_container_stack.getId()))
+        extruders = manager.getActiveExtruderStacks()
         if extruders:
             material_color_map = numpy.zeros((len(extruders), 4), dtype=numpy.float32)
             for extruder in extruders:
diff --git a/plugins/CuraEngineBackend/StartSliceJob.py b/plugins/CuraEngineBackend/StartSliceJob.py
index 1295390c22..28e442033b 100644
--- a/plugins/CuraEngineBackend/StartSliceJob.py
+++ b/plugins/CuraEngineBackend/StartSliceJob.py
@@ -333,7 +333,7 @@ class StartSliceJob(Job):
                 "-1": self._buildReplacementTokens(global_stack)
             }
 
-            for extruder_stack in ExtruderManager.getInstance().getMachineExtruders(global_stack.getId()):
+            for extruder_stack in ExtruderManager.getInstance().getActiveExtruderStacks():
                 extruder_nr = extruder_stack.getProperty("extruder_nr", "value")
                 self._all_extruders_settings[str(extruder_nr)] = self._buildReplacementTokens(extruder_stack)
 
diff --git a/plugins/GCodeReader/FlavorParser.py b/plugins/GCodeReader/FlavorParser.py
index 10f841fc43..eb19853748 100644
--- a/plugins/GCodeReader/FlavorParser.py
+++ b/plugins/GCodeReader/FlavorParser.py
@@ -275,7 +275,7 @@ class FlavorParser:
     ##  For showing correct x, y offsets for each extruder
     def _extruderOffsets(self) -> Dict[int, List[float]]:
         result = {}
-        for extruder in ExtruderManager.getInstance().getExtruderStacks():
+        for extruder in ExtruderManager.getInstance().getActiveExtruderStacks():
             result[int(extruder.getMetaData().get("position", "0"))] = [
                 extruder.getProperty("machine_nozzle_offset_x", "value"),
                 extruder.getProperty("machine_nozzle_offset_y", "value")]
diff --git a/plugins/MachineSettingsAction/MachineSettingsAction.qml b/plugins/MachineSettingsAction/MachineSettingsAction.qml
index b12f8f8696..8c2262b5b7 100644
--- a/plugins/MachineSettingsAction/MachineSettingsAction.qml
+++ b/plugins/MachineSettingsAction/MachineSettingsAction.qml
@@ -16,6 +16,8 @@ Cura.MachineAction
     property var extrudersModel: Cura.ExtrudersModel{}
     property int extruderTabsCount: 0
 
+    property var activeMachineId: Cura.MachineManager.activeMachine != null ? Cura.MachineManager.activeMachine.id : ""
+
     Connections
     {
         target: base.extrudersModel
@@ -511,7 +513,7 @@ Cura.MachineAction
                         }
                         return "";
                     }
-                    return Cura.MachineManager.activeMachineId;
+                    return base.activeMachineId
                 }
                 key: settingKey
                 watchedProperties: [ "value", "description" ]
@@ -564,7 +566,7 @@ Cura.MachineAction
                         }
                         return "";
                     }
-                    return Cura.MachineManager.activeMachineId;
+                    return base.activeMachineId
                 }
                 key: settingKey
                 watchedProperties: [ "value", "description" ]
@@ -655,7 +657,7 @@ Cura.MachineAction
                         }
                         return "";
                     }
-                    return Cura.MachineManager.activeMachineId;
+                    return base.activeMachineId
                 }
                 key: settingKey
                 watchedProperties: [ "value", "options", "description" ]
@@ -754,7 +756,7 @@ Cura.MachineAction
                         }
                         return "";
                     }
-                    return Cura.MachineManager.activeMachineId;
+                    return base.activeMachineId
                 }
                 key: settingKey
                 watchedProperties: [ "value", "description" ]
@@ -879,7 +881,7 @@ Cura.MachineAction
     {
         id: machineExtruderCountProvider
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStackId: base.activeMachineId
         key: "machine_extruder_count"
         watchedProperties: [ "value", "description" ]
         storeIndex: manager.containerIndex
@@ -889,7 +891,7 @@ Cura.MachineAction
     {
         id: machineHeadPolygonProvider
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStackId: base.acthiveMachineId
         key: "machine_head_with_fans_polygon"
         watchedProperties: [ "value" ]
         storeIndex: manager.containerIndex
diff --git a/plugins/PerObjectSettingsTool/PerObjectSettingsPanel.qml b/plugins/PerObjectSettingsTool/PerObjectSettingsPanel.qml
index a2790dcf08..596fbd2e99 100644
--- a/plugins/PerObjectSettingsTool/PerObjectSettingsPanel.qml
+++ b/plugins/PerObjectSettingsTool/PerObjectSettingsPanel.qml
@@ -17,7 +17,6 @@ Item {
 
     width: childrenRect.width;
     height: childrenRect.height;
-
     property var all_categories_except_support: [ "machine_settings", "resolution", "shell", "infill", "material", "speed",
                                     "travel", "cooling", "platform_adhesion", "dual", "meshfix", "blackmagic", "experimental"]
 
@@ -45,7 +44,7 @@ Item {
             UM.SettingPropertyProvider
             {
                 id: meshTypePropertyProvider
-                containerStackId: Cura.MachineManager.activeMachineId
+                containerStack: Cura.MachineManager.activeMachine
                 watchedProperties: [ "enabled" ]
             }
 
@@ -518,7 +517,7 @@ Item {
     {
         id: machineExtruderCount
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_extruder_count"
         watchedProperties: [ "value" ]
         storeIndex: 0
@@ -528,7 +527,7 @@ Item {
     {
         id: printSequencePropertyProvider
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "print_sequence"
         watchedProperties: [ "value" ]
         storeIndex: 0
diff --git a/plugins/PostProcessingPlugin/PostProcessingPlugin.qml b/plugins/PostProcessingPlugin/PostProcessingPlugin.qml
index b8d7258ef2..e91fc73cf4 100644
--- a/plugins/PostProcessingPlugin/PostProcessingPlugin.qml
+++ b/plugins/PostProcessingPlugin/PostProcessingPlugin.qml
@@ -384,7 +384,7 @@ UM.Dialog
                         UM.SettingPropertyProvider
                         {
                             id: inheritStackProvider
-                            containerStackId: Cura.MachineManager.activeMachineId
+                            containerStack: Cura.MachineManager.activeMachine
                             key: model.key ? model.key : "None"
                             watchedProperties: [ "limit_to_extruder" ]
                         }
diff --git a/plugins/Toolbox/src/PackagesModel.py b/plugins/Toolbox/src/PackagesModel.py
index 7892044d00..ae4cd7682d 100644
--- a/plugins/Toolbox/src/PackagesModel.py
+++ b/plugins/Toolbox/src/PackagesModel.py
@@ -76,7 +76,6 @@ class PackagesModel(ListModel):
             if "author_id" not in package["author"] or "display_name" not in package["author"]:
                 package["author"]["author_id"] = ""
                 package["author"]["display_name"] = ""
-                # raise Exception("Detected a package with malformed author data.")
 
             items.append({
                 "id":                   package["package_id"],
diff --git a/plugins/UM3NetworkPrinting/src/DiscoverUM3Action.py b/plugins/UM3NetworkPrinting/src/DiscoverUM3Action.py
index ece23507e5..be83e04585 100644
--- a/plugins/UM3NetworkPrinting/src/DiscoverUM3Action.py
+++ b/plugins/UM3NetworkPrinting/src/DiscoverUM3Action.py
@@ -24,7 +24,7 @@ class DiscoverUM3Action(MachineAction):
 
     def __init__(self) -> None:
         super().__init__("DiscoverUM3Action", catalog.i18nc("@action","Connect via Network"))
-        self._qml_url = "../resources/qml/DiscoverUM3Action.qml"
+        self._qml_url = "resources/qml/DiscoverUM3Action.qml"
 
         self._network_plugin = None #type: Optional[UM3OutputDevicePlugin]
 
diff --git a/resources/qml/Cura.qml b/resources/qml/Cura.qml
index c22fea38b4..b9febdeb32 100644
--- a/resources/qml/Cura.qml
+++ b/resources/qml/Cura.qml
@@ -306,7 +306,7 @@ UM.MainWindow
         {
             id: machineExtruderCount
 
-            containerStackId: Cura.MachineManager.activeMachineId
+            containerStack: Cura.MachineManager.activeMachine
             key: "machine_extruder_count"
             watchedProperties: [ "value" ]
             storeIndex: 0
@@ -1054,7 +1054,7 @@ UM.MainWindow
             {
                 restart();
             }
-            else if(Cura.MachineManager.activeMachineId == null || Cura.MachineManager.activeMachineId == "")
+            else if(Cura.MachineManager.activeMachine == null)
             {
                 addMachineDialog.open();
             }
diff --git a/resources/qml/Menus/ContextMenu.qml b/resources/qml/Menus/ContextMenu.qml
index e35aef5f20..1ea402d815 100644
--- a/resources/qml/Menus/ContextMenu.qml
+++ b/resources/qml/Menus/ContextMenu.qml
@@ -103,7 +103,7 @@ Menu
     {
         id: machineExtruderCount
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_extruder_count"
         watchedProperties: [ "value" ]
     }
diff --git a/resources/qml/MonitorSidebar.qml b/resources/qml/MonitorSidebar.qml
index b761b05380..80bd5c1a2e 100644
--- a/resources/qml/MonitorSidebar.qml
+++ b/resources/qml/MonitorSidebar.qml
@@ -181,7 +181,7 @@ Rectangle
     {
         id: machineExtruderCount
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_extruder_count"
         watchedProperties: [ "value" ]
         storeIndex: 0
@@ -191,7 +191,7 @@ Rectangle
     {
         id: machineHeatedBed
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_heated_bed"
         watchedProperties: [ "value" ]
         storeIndex: 0
diff --git a/resources/qml/PrepareSidebar.qml b/resources/qml/PrepareSidebar.qml
index 703cbb8844..78b6a22ef9 100644
--- a/resources/qml/PrepareSidebar.qml
+++ b/resources/qml/PrepareSidebar.qml
@@ -595,7 +595,7 @@ Rectangle
     {
         id: machineExtruderCount
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_extruder_count"
         watchedProperties: [ "value" ]
         storeIndex: 0
@@ -605,7 +605,7 @@ Rectangle
     {
         id: machineHeatedBed
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_heated_bed"
         watchedProperties: [ "value" ]
         storeIndex: 0
diff --git a/resources/qml/PrintMonitor.qml b/resources/qml/PrintMonitor.qml
index 7727f9cb52..3bfcea7025 100644
--- a/resources/qml/PrintMonitor.qml
+++ b/resources/qml/PrintMonitor.qml
@@ -78,18 +78,18 @@ Column
     UM.SettingPropertyProvider
     {
         id: bedTemperature
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "material_bed_temperature"
         watchedProperties: ["value", "minimum_value", "maximum_value", "resolve"]
         storeIndex: 0
 
-        property var resolve: Cura.MachineManager.activeStackId != Cura.MachineManager.activeMachineId ? properties.resolve : "None"
+        property var resolve: Cura.MachineManager.activeStack != Cura.MachineManager.activeMachine ? properties.resolve : "None"
     }
 
     UM.SettingPropertyProvider
     {
         id: machineExtruderCount
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_extruder_count"
         watchedProperties: ["value"]
     }
diff --git a/resources/qml/PrinterOutput/ExtruderBox.qml b/resources/qml/PrinterOutput/ExtruderBox.qml
index 56c86f1034..f0abd4cd6c 100644
--- a/resources/qml/PrinterOutput/ExtruderBox.qml
+++ b/resources/qml/PrinterOutput/ExtruderBox.qml
@@ -23,7 +23,7 @@ Item
         watchedProperties: ["value", "minimum_value", "maximum_value", "resolve"]
         storeIndex: 0
 
-        property var resolve: Cura.MachineManager.activeStackId != Cura.MachineManager.activeMachineId ? properties.resolve : "None"
+        property var resolve: Cura.MachineManager.activeStack != Cura.MachineManager.activeMachine ? properties.resolve : "None"
     }
 
     Rectangle
diff --git a/resources/qml/Settings/SettingItem.qml b/resources/qml/Settings/SettingItem.qml
index 48b3cd306d..34bf9df921 100644
--- a/resources/qml/Settings/SettingItem.qml
+++ b/resources/qml/Settings/SettingItem.qml
@@ -139,7 +139,7 @@ Item {
             {
                 id: linkedSettingIcon;
 
-                visible: Cura.MachineManager.activeStackId != Cura.MachineManager.activeMachineId && (!definition.settable_per_extruder || String(globalPropertyProvider.properties.limit_to_extruder) != "-1") && base.showLinkedSettingIcon
+                visible: Cura.MachineManager.activeStack != Cura.MachineManager.activeMachine && (!definition.settable_per_extruder || String(globalPropertyProvider.properties.limit_to_extruder) != "-1") && base.showLinkedSettingIcon
 
                 height: parent.height;
                 width: height;
diff --git a/resources/qml/SidebarHeader.qml b/resources/qml/SidebarHeader.qml
index 3a041ae499..df4f493ea5 100644
--- a/resources/qml/SidebarHeader.qml
+++ b/resources/qml/SidebarHeader.qml
@@ -607,7 +607,7 @@ Column
     {
         id: machineExtruderCount
 
-        containerStackId: Cura.MachineManager.activeMachineId
+        containerStack: Cura.MachineManager.activeMachine
         key: "machine_extruder_count"
         watchedProperties: [ "value" ]
         storeIndex: 0
diff --git a/resources/qml/SidebarSimple.qml b/resources/qml/SidebarSimple.qml
index 4b229d9807..e962d7fc8f 100644
--- a/resources/qml/SidebarSimple.qml
+++ b/resources/qml/SidebarSimple.qml
@@ -20,7 +20,6 @@ Item
     property variant minimumPrintTime: PrintInformation.minimumPrintTime;
     property variant maximumPrintTime: PrintInformation.maximumPrintTime;
     property bool settingsEnabled: Cura.ExtruderManager.activeExtruderStackId || extrudersEnabledCount.properties.value == 1
-
     Component.onCompleted: PrintInformation.enabled = true
     Component.onDestruction: PrintInformation.enabled = false
     UM.I18nCatalog { id: catalog; name: "cura" }
@@ -1116,7 +1115,7 @@ Item
             UM.SettingPropertyProvider
             {
                 id: platformAdhesionType
-                containerStackId: Cura.MachineManager.activeMachineId
+                containerStack: Cura.MachineManager.activeMachine
                 key: "adhesion_type"
                 watchedProperties: [ "value", "enabled" ]
                 storeIndex: 0
@@ -1125,7 +1124,7 @@ Item
             UM.SettingPropertyProvider
             {
                 id: supportEnabled
-                containerStackId: Cura.MachineManager.activeMachineId
+                containerStack: Cura.MachineManager.activeMachine
                 key: "support_enable"
                 watchedProperties: [ "value", "enabled", "description" ]
                 storeIndex: 0
@@ -1134,7 +1133,7 @@ Item
             UM.SettingPropertyProvider
             {
                 id: extrudersEnabledCount
-                containerStackId: Cura.MachineManager.activeMachineId
+                containerStack: Cura.MachineManager.activeMachine
                 key: "extruders_enabled_count"
                 watchedProperties: [ "value" ]
                 storeIndex: 0
@@ -1143,7 +1142,7 @@ Item
             UM.SettingPropertyProvider
             {
                 id: supportExtruderNr
-                containerStackId: Cura.MachineManager.activeMachineId
+                containerStack: Cura.MachineManager.activeMachine
                 key: "support_extruder_nr"
                 watchedProperties: [ "value" ]
                 storeIndex: 0